package com.hmdp.utils;

import lombok.RequiredArgsConstructor;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
@RequiredArgsConstructor
/**
 * 全局唯一id生成器
 * */
public class RedisIdWorker {
    private static final Long BEGIN_TIMESTAMP = 1640995200L;
    // 序列号位数
    private static final int COUNT_BITS = 32;

    private final StringRedisTemplate stringRedisTemplate;
    public long nextId(String keyPrefix){
    //1.记录时间戳
        long nowSecond = LocalDateTime.now().toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

    //2.生成序列号
        String date = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
    //3.拼接返回
        return timestamp << COUNT_BITS | count;
        }
}
